Role of [68Ga]-pentixafor positron emission tomography/computed tomography imaging in assessing disease activity in patients with lupus nephritis: A pilot study

Objective The primary objective of our study was to evaluate renal uptake of 68Ga-pentixafor in patients with lupus nephritis. Eighteen patients who satisfied the inclusion criteria were included in our study. Methods The study participants were patients with histopathologically confirmed lupus nephritis who were referred to our department for 68Ga-pentixafor PET/CT scan. We studied the renal images in these patients for uptake patterns based on purely visual as well as semi-quantitative parameters. The visual parameters included uptake relative to the spleen and liver. Semi-quantitative analysis involved the uptake as given by SUVmax. These parameters were correlated with the patients’ biochemical as well as histological parameters. Kendall’s tau-b test was used to look for an association between renal uptake by visual assessment and histopathological findings. Mean SUVmax values were compared by using the Mann–Whitney U test and a p value < .05 was considered to be statistically significant. Results No significant association between the mean renal SUVmax of the bilateral kidneys in pentixafor PET and histopathological class was observed. We did not observe any heterogeneity in uptake patterns that could be attributed to the disease process in our patients. Conclusion 68Ga-pentixafor PET is not a suitable imaging modality for assessment of disease activity in lupus nephritis patients. There is a void in non-invasive testing for patients with this chronic and often disabling condition which calls for further research in this area.